## Search found 11 matches

Sun Feb 28, 2016 11:50 pm
Forum: *Constitutional and Geometric Isomers (cis, Z and trans, E)
Topic: How to Differentiate between Cis and Trans
Replies: 1
Views: 282

### Re: How to Differentiate between Cis and Trans

The cis prefix means the atoms are on same side. For example, in dichloroethene, you can have the two chlorine atoms both on the same side or on the opposite sides. If you decide to draw this out and put chlorine on opposite sides, you would have a trans-1,2-dichloroethene, with the chlorine atoms a...
Sun Jan 31, 2016 10:52 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Week 4 WED Lecture
Replies: 1
Views: 168

### Re: Week 4 WED Lecture

If you have a voltaic cell, the anode is continuously losing electrons and the cathode is continuously gaining electrons. If this were to continue, one side would be negatively charged and the other, positively charged. At one point, electron transfer would stop from anode to cathode because the ano...
Sun Jan 24, 2016 11:09 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: Homework Problem 8.37
Replies: 2
Views: 339

### Re: Homework Problem 8.37

We use the first equation you mention because that's the only information given in the problem. You can also find the enthalpy of vaporization by the second equation but we are not given the enthalpy values for the liquid and vapor. We do know that enthalpy of vaporization is the heat required to va...
Sun Jan 17, 2016 11:01 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Bond Enthalpies for HW 8.67
Replies: 1
Views: 278

### Re: Bond Enthalpies for HW 8.67

I'm pretty sure that the 6 is being multiplied with by the enthalpy of a C-C bond of benzene. In the answer key, it just writes out "C-C bonds, resonance," and it looks like a single bond. But, the value 518 kj/mol is the bond enthalpy for a C-C bond a benzene structure. So while the answe...
Sun Jan 17, 2016 10:42 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: HW Question 8.73
Replies: 1
Views: 286

### Re: HW Question 8.73

You don't need to break the C-H bonds of C2H2 because these bonds reappear in the product. On the reactant side, there is a total of 6 C-H bonds. Each C2H2 has two C-H bonds, and there are 3 mols of C2H2 (2x3=6). The product, benzene, has a ring structure with 6 carbons, and each carbon has a H atta...
Wed Jan 06, 2016 9:48 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Homework Question Ch. 8 #55, Hess's Law
Replies: 2
Views: 221

### Re: Homework Question Ch. 8 #55, Hess's Law

Yeah, I assumed the solution manuels' coefficients were correct. Thanks for your input!
Wed Jan 06, 2016 8:28 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Homework Question Ch. 8 #55, Hess's Law
Replies: 2
Views: 221

### Homework Question Ch. 8 #55, Hess's Law

Question states that from the given two standard reactions enthalpies, to calculate the reaction enthalpy for the production of metallic barium in the reaction (pic of question attached). I was having some difficulty with it, so I checked the solution and the aluminum metal standard reaction enthalp...
Sat Nov 28, 2015 7:40 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Video Submission, Le Chatelier's Principle in the Homework
Replies: 1
Views: 418

### Re: Video Submission, Le Chatelier's Principle in the Homewo

Once again, this is Rebecca Chen and Trina Kim's Chemistry Community Video Submission explaining Le Chatelier's Principle in the context of problem 11.71 from the textbook homework problems. This video is formatted for mp4.
Sun Nov 22, 2015 7:32 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Video Submission on Le Chatelier's Principle
Replies: 1
Views: 397

### Video Submission on Le Chatelier's Principle

Attached is Rebecca Chen and Trina Kim's Chemistry Community Video Submission.
Sun Nov 15, 2015 8:24 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Insignificant change in molar concentration
Replies: 1
Views: 213

### Insignificant change in molar concentration

When is change in molar concentration negligible? Is there a certain K value to use as a standard?
Sun Nov 08, 2015 4:06 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: Molecular Orbital Theory
Replies: 1
Views: 268

### Molecular Orbital Theory

So for a homonuclear diatomics for an element with an atomic number greater than 7, why is the order of the pi bonding orbital and sigma bonding orbital switched in the 2p orbital?